Switch with automatic shutdown (CB21258E)

This circuit was found in Maxim documentation from the 1990s. The RC circuit determines the trigger time.

Simple Transistor Tester I (CB18917E)
We found this simple transistor tester in a French publication in 1981. It uses a common analog...
Speed Game (CB22072E)
Who is faster? or reaction game are other names for this circuit that we find in old...
Photodiode Amplifier (CB4950E)
This circuit is from an 80's component manual. The components are from the time, but the circuit...